Abstract: Intake manifolds for an internal combustion engine include a first insert configured as a port cap that has a bottom surface defining a first perimeter recess configured to receive a first sealing member, a second insert configured as a port cap that has a bottom surface defining a second perimeter recess configured to receive a second sealing member, and a main body having a first set of runners extending in a first direction therefrom and a second set of runners extending in an opposite direction therefrom. Both the first set of runners and the second set of runners each terminate at a back end with a flange that defines a socket configured to receive one of the first and second inserts, respectively. The first insert and the second insert are seated in their respective socket, and each are made of a material that is chemically resistant to coolant fluid.

Abstract: An intake manifold assembly is disclosed that utilizes a barrel valve apparatus comprised of segments and connectors. The barrel valve apparatus and its housing component can be tapered and flexible. A protrusion such as a draft can be used to seal the performance of the barrel valve apparatus without a seal. Openings in the barrel valve apparatus can possess an integrated bellmouth shape.